METALLURGY OF IKOiST AND STEEL.
the subject of a paper by Ball and Wmgham,* in-which they showed that as much as 7 per cent, could be alloyed to iron, and that a specimen with 4 per cent, forged well both hot and cold. It was found that the alloys were very hard, so that when the content was over 7 per cent, the metal could not be cut by a good tool. The experiments showed a considerable increase in tensile strength in the case of higher copper., but no great weight can be given to the determinations., for the methods used in making the alloy and in cutting the tests were too crude- for conclusive results.
It is not easy to make a comparison between the ductility of high-copper and low-copper steels, for at works using .such material it is customary to keep a fairly constant percentage in the mixture rather than to vary between wide limits. A limited number of heats have been grouped together in Table XVII-I, and although the list is not as long as might be desired, it should be -considered
TABLE XVII-I. Properties of Low-Copper and High-Copper Angles.
Made by The Pennsylvania Steel Company, 1898.
1 *>• to -0 fl cf as
a d d d ° d
Thickness in 1 Copper; perc< Number of he Ultimate stre pounds per square inch Elastic limit; pounds per square inch 1* ll Reduction of per cent. Elastic ratio; per cent.
.10 11 61376 44152 27.52 66.80 71.9
A .85 17 60283 43841 27.88 69.01 72.7
.10 10 58965 42218 28.85 55.50 . 71.6
.85 11 59630 48478 29.02 57.86 72.9
that the heats were all made within a short period in the same Bessemer, and were all rolled in the same mill. No difference is to be found in the ultimate strength between steels with high and low copper, although all the heats were made in the same way as nearly as possible, the workmen not knowing either in the Bessemer department or in the rolling mill what kind of iron was in use.
The high copper gives-a slightly higher elastic ratio, which is a benefit, and a better elongation and reduction of area. These re-
* On the Influence of Copper on the Tensile Strength of Steel. Journal I. and S, L, Vol. 1,1889, p, 123. . , ..............